Good suggestion, go for it! You, yes you, are part of the mythical the developers. And beautiful figures somewhere could be done by you. No better way to communicate exactly what you mean.
In your first post you said: “I reproduced these plots using PyPlot.jl and GR.jl, they look much better”. I suggest to produce a document with code & graphic for the “ugly” plot on the left and PyPlot and GR on the right. If done well, it would be helpful also for people deciding between different approaches.
[So far I used PyPlot or, ähem, R for plotting and only know Plots.jl from the interesting JuliaCon16 presentation. But now curious having a look at the mentioned tutorial, I must say, I’m very very impressed by this beautifully thought out document. And I like that it stays clear and doesn’t over-distract with decorations. Don’t want to know how many nights must have gone into it… 
]